27 Jul
2007
27 Jul
'07
3:50 p.m.
On 27 Jul 2007 at 14:47, CRC wrote:
I've been keeping a pair of HP Interferometers
going for years
by occasionally putting them in pure He for several weeks, all the
time measuring the output and waiting for it to come back to spec. If
you have an old, well-sealed tube that has gone gassy due to helium,
you can rescue it by putting it in a high vacuum for a couple of
months...
Lessee, Dalton's Law, right? ...and the porosity of glass...
Cheers,
Chuck